Expansible self retracting linkage



Sept. 1, 1959 Filed Nov. 2, 1956 K. c. AUGENSTEIN ETAL' 2,901,895

EXPANSIBLE SELF RETRACTING LINKAGE 2 Sheets-Sheet 1 INVENTORS KARL C. AUGENSTEIN PAUL LEVINGER BY m fla mg am/ow ATTORN EYS P 1 59 K. c. AUGENSTEIN ET AL 2,901,895

EXPANSIBLE SELF RETRACTING LINKAGE Filed Nov. 2, 1956 2 Sheets-Sheet 2 INVENTORS KARL C. AUGENSTEIN PAUL LEVINGER BY QZz %77oam$m/0w ATTORNEYS Patented Sept. 1, 1959 EXPANSIBLE SELF RETRACTING LINKAGE Karl C. Augenstein, Cranston, and Paul Levinger, Providence, R.I.; said Augenstein assignor to Speidel Corporation, Providence, R.I., a corporation of Rhode Island Application November 2, 1956, Serial No. 620,133

4 Claims. (Cl. 63-5) The present invention relates to expansible, self-retracting linkages for bracelets, such as watch bracelets and the like, and more particularly to such linkages having pivotally connected links associated with retracting springs.

The ornamental designs of conventional linkages of this type are limited by the mechanical nature of the links. Consequently, many desirable ornamental designs which are possible with non expansible bracelets cannot be used.

In order to overcome this disadvantage linkages can be provided which include non expansible portions visi- ,ble from above the wrist and a self retracting, expansible portion located below the wrist. In certain cases it is preferable and in other cases necessary that the expansible portions comprise a lazy tongs type linkage, which consists of a series of top and bottom links pivotally at- .tached at their central and end portions with a helical spring associated with each central pivot. However, the relatively small maximum expansibility per unit of retracted length of a conventional lazy tongs linkage requires the length of the expansible portion to be so long and consequently the length of the non expansible portions to be so short that in contracted position about the wrist a large part of the expansible portion is visible from the top and sides of the wrist and the overall effect is an unsymmetrical one. Otherwise, the bracelet cannot be expanded enough to slip it over the hand to the wrist. In fact, even when the total length of the non expansible portions is relatively short, the length of the expansible portion is still inadequate to give the proper amount of bracelet expansibility and consequently it is difiicult, if not impossible, to slip the bracelet over the wearers hand to his wrist.

In order to understand this more fully it is pointed out that the maximum expansibility per unit of retracted length of lazy tongs arrangements is determined by the complished by making the individual links of the lazy tongs type linkage narrower than the links of conventional lazy tongs type linkages. This is made possible by using helical springs having smaller coil diameters. Sufficient retraction force is provided by providing two helical springs associated with each link and located in the end pivotal connections associated with the link instead of one spring located in the central pivot as in conventional lazy tongs type linkages. Another object is to provide a partially expansible and partially non expansible linkage which has a relatively long non expansible portion capable of embodying non expansible bracelet designs, and a relatively short lazy tongs type expansible self-retracting portion, and yet which has a sufficient total expansibility to be easily slipped over the hand. In accordance with the present invention it is possible to provide such a partially expansible and partially non expansible linkage having an expansibility equal to the expansibility of a linkage of the same length which is made entirely of a conventional lazy tongs type linkage.

Another object of the present invention is to provide such a partially expansible and partially non expansible linkage in which the lazy tongs type expansible portion can be expanded a greater distance per unit of retracted length than conventional lazy tongs type linkages and hence in which the expansible portion is capable of expanding sufficiently for the entire linkage to be easily slipped over the hand of the wearer.

Yet another object is to provide an improved expansible self retracting linkage for bracelets or the like.

Further objects and advantages of the invention will be apparent from a consideration of the following description and the accompanying drawings wherein three embodiments of the invention are shown.

In the drawings:

Fig. 1 is a top plan view of a watch bracelet showing one embodiment of the present invention in retracted posit-ion.

Fig. 2 is a view similar to Fig. l with the expansible portion of the linkage expanded sufliciently so that, with a watch attached between the ends, the watch and bracelet may be slipped over the wearers hand to encircle his wrist.

Fig. 3 is a top plan view of a part of the expansible,

, self-retracting portion of the linkage with portions of the minimum width 'of the links, which in turn is determined by the minimum coil diameter of a helical spring which will give satisfactory retraction. In conventional lazy tongs linkages employing a single coil spring for each pair of top and bottom links and located in the central pivot, the minimum coil width which will give proper retraction requires link widths so great that substantially the entire length of the bracelet must be expansible in order to have enough expansibility to be easily slipped over the hand to the wrist. Consequently, if any substantial portion of the bracelet is changed from an expansible linkage to a non expansible linkage the total expansibility of the bracelet is inadequate.

' An object of the present invention is to provide a lazy tongs type of self-retracting expansible linkage which can be expanded a greater distance per unit of retracted length than conventional lazy tongs type linkages and hence in which the short length of expansible portion is capable of expanding sufficiently for the linkage to be easily slipped over the hand oi the wearer. This is actop shells broken away.

Fig. 4 is a bottom plan view of part of the expansible self-retracting portion of the linkage with portions of the bottom shells cut away.

Fig. 5 is a section taken along line 99 of Fig. 3.

Fig. 6 is an exploded view of one of the top links.

Fig. 7 is an exploded view of one of the bottom links.

The watch bracelet 1 comprises a central expansible, self-retracting portion 2 having on either end thereof nonexpansible portions 3 and 4-. Each non-expansible portion 3 and 4 has a terminal connector 5 for connecting the linkage to a watch or identification locket or the like and is comprised of a series of links 6, pivotally attached to each other so that the non-expansible portions may oncircle parts of the wrist of the wearer. In the embodiment illustrated decorative elements 6a are provided in the links 6.

Expansible portion 2 comprises a series of top links 8 and bottom links 9 (Figs. 3 to 7) pivotally connected at their central and end portions by means of hollow tubular members 10, 12 and 14, extending from and integral with 20 of each top liner receives the central hollow tubular meniber 12 of one adjacent bottom link, the aperture 18 at one'end of such top liner receives the tubular member of another adjacent bottom link and the aperture 22 at the other end of the'top liner receives the tubular member 14 of a third adja ent bottom link. The hollow tubu- Iar. members are retained in the apertures by peeningover the ends-10a, 12a and 14a as shown in Fig. 5.

' Each top link 8 is provided with a top shell 26 which has. adownwardly extending side wall 27 and is attached to. liner 24 by four tabs 28 which extend downwardly from side walls 27 into cut away portions or notches 3c in the sides of liner plate 24 and thence inwardly into the recesses in the bottom ofbase member 24 formed by upwardly dished portions 48. The edges 32 of the recesses in the walls 27 rest onv the rojections 34 of the liner 24.

Each bottom link 9 has a bottom shell 36 which has an upwardly extending side wall 37 and is attached to the bottom liner or' plate 16 by means of four tabs 38 which extend from the side walls 37 upwardly into notches 40 in the sides of liner 16 and thence into the recesses formed by the downwardly dished portions 46 of liner 16. The 42 of'recesses' in the wall 37 are supported on the shelves 44 of the base member 16.

The coil 51 of a helical spring 50 extends through each hollow tubular member 10. An elongated end 52 of the spring 50 is located in the associated top link 8 and has a hook 53 which extends into the hollow tubular member 12 associated with that top link. The other end 54 of the spring 50 is' located in the adjacent bottom link 19 from which the hollow member 10 extends and abuts against the wall 37 of the bottom shell of such bottom link; The coil" 56 of another helical spring 58 extends through the hollow tubular member 14. One elongated (and 60 thereof is located in the associated top link 8 and has a hook 62 which extends into the hollow member 12 of such top link. The other end 57 of the spring 58 is located in the adjacent bottom link from which the tubu- Iar'member 14 extends and abuts against the wall 37 of the bottom shell 36 of such bottom link. Thus each top link has associated. therewith a pair of springs 50 and 58 one for each end pivotal connection of the link (10 and 14') and one elongated end (52 and 60) of each of these pair of springs is located in the top link and extends in the form of a hook (53 and 62) into the central pivotal connection 12 thereof. These springs retain the expansible self-retracting portion 2 in retracted position and permit but resiliently resist the expansion thereof.

The expansible portion 2 is capable of expanding substantially' more per unit of retracted length than conventional lazy tongs type linkages because the Width of each of the top and bottom links 8 and 19 is substantially less than the width of the links of conventional lazy tongs type linkages. This decreased width is made possible by making the coil diameters of the springs 50 and 58 substan tially less than the coil diameters of conventional helical springs located in the center pivotal connections of conventional lazy tongs type linkages. It is possible to make the coil diameters substantially less and still retain the same expansibility and self-retracting action because there are, for example, twice as many springs per unit of retracted length. 7

The end of each of the end bottom links is pivotally connected to one end of a top half link 8a the other end of which is pivotally connected to the topside of lip 8b of a terminal, connector 80. The end of each of the end top links is pivotally connected to one end of a bottom half link 90 the other end of which is pivotally connected to the underside of lip 8b of terminal connector 80. One of the terminal connectors 80 is pivotally connected to theend link of non-expansible portion 4 and the other terminal connector is pivotally connected to the end link oi the other non-expansible portion 3. Each "terminal connector hc has a. portion 8d which is'shaped and located so. that when; the bracelet isv retracted it looks like the 4 other half of the top half link 8a which is pivotally connected to it.

The terms top and bottom, upper and lower as used herein refer to the positions of the various parts with relation to each other. For example, if the bracelet is turned upside down, so that the top links are below the bottom links, they are still top links and the side walls thereof still extend downwardly with relation to the bottom links;

Whileonly one embodiment is shown in the drawings, it is to be understood that this disclosure is for the purpose of illustration and that various changes in shape, proportion and arrangement of. parts and the substitution of equivalent elements may be made without departing from the scope of the invention as set forth in the appended claims.

We claim:

1. An expansible, self-retracting linkage comprising a series of elongate top links, a series of elongate bottom links, means pivotally interconnecting the top and bottom links at their centers and means pivotally interconnecting the top and bottom links at their ends to form a lazy tongs arrangement, each of said end connecting pivotal means being hollow and having a coil spring located therein with its ends associated with the adjacent top and bottom links and operative to normally maintain them in retracted position, each of said hollow end connecting pivotal. means fitting closely around the coil of its spring but loosely enough so as not to bind the s ri the width of the links being only slightly greater than the width of said end connecting pivotal means, said links being side by side and abuttin each other in retracted position, whereby the coil diameter of said coil springs may be less than the coil diameter when coil springs are located only in the center connecting pivotal means and hence the width of said links may be less than the width of the links when coil springs are located only in the center connecting pivotal means, so that the expansibility of such linkage per unit of retracted length may be substantially greater than the expansibility per unit of retracted length when coil springs are located only in the center connecting pivotal means and the same number of links can be located in a lesser linkage length while giving the same amount of expansion.

2. A linkage according to claim 1 wherein each center connecting pivotal means is hollow and one end of each spring is formed with a hook, the hooks of each pair of springs extending into the hollow center connecting pivotal means of a link with which said pair of springs is associated. I

3. An expansible, self-retracting linkage comprising an expansible, self-retracting portion extending longitudinally of the linkage, a non-exp'ansible portion at each end of said expansible portion, said expansible portion comprising a series of elongate top links, a series of elongate bottom links, means pivotally interconnecting the top and bottom'links' at their centers, and means pivotally interconnecing the top and bottom links a their ends to form a lazy tongs arrangement, each of said end connecting pivotal means being hollow and having a coil spring located therein for normally maintaining the top and bottom links pivotally connected by said each end connecting pivotal means in retracted position, each of said hollow end connecting pivotal means fitting closely around the coil of its spring but loosely enough so as not to bind the spring, the width of the links being only slightly greater than the width of said end connecting pivotal means and said links being side by side and abutting e'ach other in retracted position, whereby the coil diameter of said coil springs may be less than the coil diameter when coil springs are located only in the center connecting pivotal means and hence the width of said may be lessthan the Width of the links when coil springs are located only in the center connecting pivotal means, so that, the expansibility of said linkagev per unit, oi re.-

tracted length may be substantially greater than the expansibility per unit of retracted length when coil springs are located only in the center connecting pivotal means and the same number of links can be located in a lesser linkage length while giving the same amount of ex pansion.

4. A linkage according to claim 3, wherein each center connecting pivotal means is hollow and one end of each spring is :formed with a hook, the hooks of each pair of springs extending in to the hollow center connecting pivotal means of a link with which said springs are associated.

References Cited in the file of this patent UNITED STATES PATENTS 223,669 Edge Jan. 20, 1880 6 Bennett Feb. 7, 1905 Bennett Nov. 20, 1906 Bennett Ian. 25, 1910 Jones Dec. 10, 1929 Carlson Nov. 11, 1930 Sand May 14, 1935 Augenstein Dec. 30, 1941 Augenstein Dec. 30, 1941 Pinson May 4, 1954 FOREIGN PATENTS Great Britain 1898 Switzerland Mar. 17, 1930 OTHER REFERENCES Germany, G 9754, III/44a, printed May 30, 1956-. 

